CA2050863A1 - Method and apparatus for attaching binding to extensible material - Google Patents

Abstract

Abstract of the Disclosure The invention provides a method and apparatus for folding lengthwise and clamping a flexible binding, while leaving the edges of the clamped binding free to be separated such that the edge of a length of extensible netting may be inserted between the free edges. A
progressive linear clamp is provided for progressively clamping the combined netting and binding material as the netting is inserted to thereby permit an operator to obtain a substantially uniform stretch of the edge of the netting material, and to apportion the netting evenly along the binding. With the netting material thus inserted and clamped between the edges of the binding, a feed mechanism is positioned to engage the combined binding and netting and feed it to a sewing machine to permanently secure the materials together.

Description

;~3~ ~3 METHOD AND APPARATUCl FO~
ATTACHING BINDING TO EXTENSIBLE MATERIAL
Background of the Invention This application relates to the attachment of a binding to extensible material, and specifically to a method and apparatu3 which assists an operator of a fastening machine, such as a sewing machine, in preparing the materials for joining, and which conserveæ operator time and allows concentration of operator attention on the task of properly fitting an edge of the extensible material into the binding, after which the two are clamped and then secured.
Although it will be apparent that the invention is applicable to many different forms of material, and that some features of the invention are per se novel, the specific application for which the invention was made concerns -the ~ecuring of an ed~e of a piece of flexible netting, made of extensible cord, to a woven webbing which serve~ as the binding. There is a demand for such bounded flexible netting, at present, for a variety of uses, one of which is as a hold down device in automobiles and trucks.
The webbing is somewhat qtiff, usually in the order of two to three inches in width, and of any desired lPngth. The netting i~ available in a variety of widths, and due to the nature of the open netting and extensibility (stretch) of the cord from which the netting is constructed, it is considerably adjustable in width beore securing to the webbing.
At present, to perform -this task, an operator must fold the webbing along its length, roughly in half, insert an edge of the netting into the fold and proportion the 3 ~ 3 ~31 i`; ~ r3 netting along the binding webbing, hold all of this together~ and feed the assembled parts through a sewing machine or the like to secure the netting into the webbing.
Obviously, the longer the parts to be joined, the more difficult is this task, and the more likely that there will be lack of uniformity in successively made joined parts.
The same difficulties could result, for example, in attempting to join a more stable piece of cloth to a quite flexible and exten~ible binding. In any even-t, there is a need to stabilize the parts, allow the operator to fit them together, adjust the relative positions of the parts as needed, clamp them in the final position, and then sew or otherwise secure the parts together. This need applies to a variety of situations in joining such pieces, and to parts cf varying length, but the need is more severe as the parts are longer.
Summary of the Invention The invention provides methods and apparatus for folding lengthwise and clamping a flexible binding, while leaving the edges of the clamped binding free to be separated. With the binding 30 folded and immobilized, the operator can fit the edge of a length of extensible netting between the fold of the binding and bring into play a progressive clamp which firmly holds the joined portions of the netting and binding as the operator proceeds. This allows the operator to concentrate on obtainin~ a substantially uniform stretch of the edge of the netting material, and to apportion such edge evenly along the binding. The clamped parts, once fully fitted together, are rJ ~

then fed throu~h a sewing machine or the like to secure them together.
More particularly, an apparaltus is provided in which a length of webbing ~serving as the binding) is supported with one of its lonyitudinal edges fitted along a channel in a supporting table, and the opposite edge of the webbing fitted against a lip on a fold plate which is hinged to the table along, and parallel to, the channel. The plate can be pivoted over the channel, to fold the length of webbing roughly in half ~or to some other proportion).
Spaced along the plate, near its hinge axis, are a plurality of slots which allow access for clamp fingers which can reach through the slots and pinch the foldea edge of the webbing, allowing the fold plate to be opened. At this point, the webbing is secured in folded position, and the free edges of the webbing can be separated to access the space within the fold.
The operator then can begin to insert the edge of the netting piece into the fold of the webbing, working from one end thereof, and apportioning the netting to place it evenly along the webbing, whereby there will be approximately even tension in the netting part of the joined pieces. As this task proceeds, a progressive clamping device is brought into play, most conveniently under operator control through a foot pedal. This clamping device has a pair of spaced apart wheel~ or pulleys, aligned to move along the channel, with an endless belt reeved around them. The wheels and belt are mounted on a carrier which is supported to be reversibly driven along the channel, under operator control. As the netting is placed into the folded ~ J~

and clamped webbing, the operator can advance the progressive clamping device while proceeding ahead of it to continue to fit the netting edge into the folded webbing.
The clamping device holds the interfitted netting into the ~ebbing, by pressing down on the assembled segments, and will continue to do so throughout the length of the webbing piece. Preferably, the belt is a toothed belt, with the teeth arrayed outward to contact the folded over side of the webbing, and as the progressive clamp moves along, there is no relative motion between the belt and the webbing surface, thus the progre~sive clamping device does not tend to displace or disarray the parts which the operator has placed together, but instead stabilizes these parts and allows the operator to proceed without concern for displacement of the netting edge just fitted into the clamped, folded webbing.
Once the operator has finished the fitting task, the progressive clamping device has control over the full length of the interfitted netting and binding~webbing. At this juncture, a separate feeding head comes into play and is caused to move parallel to the channel ~and the progressive clamping device) into alignment with the interfitted parts. An elongated feeding clamp, on the movable feeding head, engages the full length of the interfitted parts, the progressive clamp is released, and the feeding head carie~ the interfitted parts away, sliding them along the channel and into and through a sewing machine head where the parts are stitched together, or otherwise joined. Vnce this feeding head clears the area of motion of the progressive clamping device, it can be located in its home position and the operator can enter another piece of ~ ~ p~

webbing between the fold plate lip and channel, cause it to be folded and clamped, and begin fitting the next piece of netting.
The principal object of th~ invention is to provide a novel method and apparatus for joining a folded binding to an edge of a piece of material, particularly where one or both of the material and binding are flexible and extensible and must be properly apportioned along the length of their joint; to provide such a method and apparatus wherein the binding i5 folded lengthwise and immobilized with its edges free for receiving the edge of the material to be edge bound; to provide a novel progressive clamping device; to provide such a clamping device which will progressively engage and hold parts to be joined, as by sewing, without relative movement between the contact of the clamping device and the interfitted materials, to provide such a progressive clamping device in an apparatus which assists an operator in the process of placing an edge of material into a folded over binding, to provide a feeding head which will accept transfer of the interfitted pieces from the progressive clamping device at the end of its operation, and move the parts into a sewing head or other appropriate apparatus for permanently securing the pieces together.
Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.
Brief Description_of the Drawin~s Fig. 1 is a perspective view of the apparatus of the present invention;

& ~ 3 Fig. 2 is an elevational view of the folding and clamping station with the folding plate and clamping fingers in a retracted position;
Fig. 3 is an elevational view of the folding and clamping station with the folding pla-te and clamping fingers in an extended position;
Fig. 4 is a perspective view of the progressive linear clamp;
Fig. 5 is a perspective view of the feed mechanism; and Figs. 6-9 are diagrammatic views of the steps of the method of attaching binding to an extensible material in accordance with the present invention.
Detailed Description of the Preferred Embodiment Fig. 1 generally shows the apparatus for folding and clamping a pliable binding web 11 to a pliable netting material 13 and for sewing the completed structure. The apparatus includes a worktable 10 having an elongated channel 12 formed therein and extending from a folding and clamping ~tation 14 to a sewing station 16.
A progressive linear clamp 18 is mounted for movement parallel to the channel 12 and includes an endle~s belt 20 forming a clamping surface for progressively clamping material within the channPl 12. The belt 20 is preferably a toothed belt having outwardly extending teeth for po~itively pres~ing the material in clamping engagement with the channel 12. The progressive linear clamp 18 is movable into and out of the folding and clamping station 14 for purpo~es to be described further below.

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A feed mechanism 22 is supported from an elevated drive rail structure 24~ The feed mechanism 22 is movable in a path parallel to the channel 12 along substantially the entire length of the table 10 and includes means for gripping material within the channel 12 and sliding it from the folding and clamping station 14 to the sewing station 16, In operation of the apparatus, an elongated strip of webbing or binding material 11 is placed in the folding and clamping sta-tion such that half of the width of the material 11 extends across the width of the channel 12, and the remaining half of the material 11 extends across a folding plate 26 mounted for pivotal movement adjacent to a longitudinal edge of the channel 12. The plate 26 is then pivoted forwardly to fold the material 11 in half.
Subsequently, a set of clamping fingers 28 is actuated to clamp the folded material 11 along the fold line such that the folding plate 26 may be pivoted upwardly away from the material 11 and the material will be maintainea in its folded position within the channel 12.
With the webbing material 11 clamped in place, an operator may then place the edge of a netting material 13 between the free lips of the webbing material 11 e~tending forwardly of the clamp fingers 28. As material 13 is placed between the lips of the webbing material, the progressive linear clamp 18 is caused to move forward incrementally such that the belt 20 engages and presses together the lip portions of the webbing material 11 to thereby hold the webbing 11 and netting 13 together as a combined structure.
The design o~ the progressive linear clamp 18 is such that b ~ j S

the belt is caused to advance into contact with the webbing material at the same lineal rate as the clamp 18 is advanced whereby relative movement between the webbing and the portion of -the belt 20 in contact with the webbing is avoided.
Wi-th the progressive linear clan~p 18 positioned over the entire length of the combined webbin~ and netting structure, the feed mechanism 22 is brought into position over the combined structure at the longitudinal edge opposite from the clamp fingers 28. With the feed mechanism 22 in position over the combined web and netting structure, the means for gripping the material is actuated to engage and press the combined structure against the channel 12, and the progressive linear clamp 18 and clamping fingers 28 are moved out of clamping engagement with the combined structure. Thereafter, the feed mechanism 22 slides the combined web and netting structure longitudinally along the channel 12 to the sewing station where the webbing 11 and netting 13 are sewn together adjacent to the outer longitudinal edge of the lips of the webbing material 11.
Referring now to Fig. 2, the particular structure of the folding and clamping station 14 will be described in further detail. Initially, it should be noted that the table 10 includes a primary support structure 30 for supporting a plurality of plates forming the work surface.
A front plate 32 is ~upported by the support structure 30 forwardly of the channel 12 and both the front plate 32 and channel 12 are preferably formed of stainless steel. The front plate 32 includes a material trough 34 at a forward edge thereof for catching any material which may slip off the horizontal portion of the plate 32.
A rear plate 36 i8 supported by the primary support 30 rearwardly of the channel 12 and forms the ~upport surface for the folding plate 26, the linear progressive clamp 13 and the actuating mechanisms for these devices.
The folding plate 26 is mounted to the rear plate 36 by means of hinges 37 and is preferably formed having a length of approximately ~ ft. The olding plate 26 is actuated for pivotal movement by means of three equally spaced air cylinders 38. The air cylinder~ 38 are mounted to the rear plate 36 by pivot means 40 at one end, and at the other end are each attached to a pivot bracket 42 extending from the back side of the folaing plate 26.
The air cylinders 38 are double acting ~ylinders and may be actuated to extend the folding plate 26 to a horiæontal position overlying the entire width of the channel 12, as ~een in Fig. 3, and may be actuated in the opposite direction to position the folding plate 26 at a ~ub~tantially vertical position adapted to permit webbing material to be inserted along the channel 12 and the folding plate 26.
It should be noted that the folding plate 26 include~ a lip 44 located along the longitudinal edge of the plate 26 distal from the hinge 37. The lip 44 acts to retain the webbing material 11 in contact with the plate 26 a~ the plate 26 is pivoted forwardly over the channel 12.
In addition, the rearward edge of the front pla-te 32 defining the forward longitudinal edge of the channel 12 ~,~.?~ 3 acts to retain the opposing longitud:Lnal edge of the webbing 11 during the folding operation.
Thus, the folding plate 26 and channel 12 are configured such that the webbing material 11 will be held against movement during the folding operation whereby the webbing 11 will be folded in half and positioned entirely within the width of the channel 12.
The folding plate 26 is formed with slotted portions 46 extending from the hinged edge toward the lip edge 44. The slots 46 have a width which is slightly larger than the width of the clamp fingers 28 and each of the slots 46 is aligned with one of the clamp fingers 28.
The clamp fingers 28 are preferably uniformly spaced along the length of the folding plate 26 and, in the preferred embodiment, twelve fingers are provided with each finger ~paced approximately 2 inches apart from adjacent fingers.
Each clamp finger 28 is supported for movement toward and away from the channel 12 by an actuation and support structure 50 which ex~ends through a slot 48 formed in the primary ~upport 30 and rear plate 36. In addition, the actuation and support structure 50 includes means for actuating the clamp fingers 28 for pivotal movement down into contact with material in the channel 12.
Referring to Figs. 2 and 3, the actuation and support structure 50 includes a support bar 52 extending substantially vertically through the ~lot 48. The support bars 52 for each of the structures 50 are preferably supported by a common lonyitudinal beam 54, and the beam 54 includes forwardly extending tabs 56 at either end for ~3~' engaging a support bracket 60 at a pivotal mounting point 62. Thus, the actua-tion and support structures 50 are mounted for pivotal movement about an axis loca-ted below the table 10 and are joined together such that all of the ~tructures 50 will move simultaneously forwardly or rearwardly through their respective slots 48.
A pivot bar 64 extends downwardly from the longitudinal beam 54 and is connected to one end of a double-acting cylinder 66. The other end of the cylinder 66 is ~upported from a bracket 68 attached to the bottom of the table 10. The cylinder 66 acts to effect the pivotal movement of the actuation and support structures 50 about the pivot point 62.
The actuation and support ~tructure 50 is further provided with a double-acting finger actuation cylinder 70 supported by a lower end of the support bar 52 and having an upper piston end connected to a rearward leg 72 of the finger 28 by means of an extension bar 74. The clamp finger 28 is mounted to the support bar 52 at a pivot point 76 such that, upon actuation of the cylinder 70, the forward portion of the clamp finger 28 will be caused to pivot to an upper or lower position.
It should be noted that the front portion of the finger 28 includes a contact tang 78 extending substantially perpendicular to the longitudinal axis of the finger 28 and is adapted to contact the webbing material located within the channel 12.
The length of the slots 46 in the folding plate 26 are .~uch that the clamping fingers 28 may extend through the slots 46 when the pivot point 76 i~ in its forwardmost position and when the cylinder 70 has been actuated to move the tang 78 downwardly into the channe1 12, In addition, the slots 46 also allow the forwardmost edge of the fingers 28 to move through the plate 26 when the plate 26 is in its upwardly pivoted position and the cylinder 70 has positioned the finger 28 such that the tang 78 is in its upper position. Thus, the plate 26 and the fingers 28 are freely movable relative to each other regardles~ of their respective positions.
It should also be apparent that the arc of travel of the pivot point 76 is large due to the distance between the pivot 62 and the pivot 76 such -that the movement of the actuation and qupport structure 50 adjacent to the finger 28 is substantially linear as it moves to locate the clamp finger 28 at a forward position where the tang 78 may be pivoted es~entially downwardly into contact with the webbing material 11 closely adjacent to the fold line of the material.
Referring now to Fig. 4, the particular structure of the progressive linear clamp-18 will be described. The progres~ive linear clamp includes a clamp base 90 for supporting various components of the clamp 18 and a pair of guide rails 92, 94 are received in bores formed in a pair of bearing block~ 96, 98 attached to the bottom of the clamp ba~e 90. The rails 92, 94 are supported by a pair of rail mountings 100, 102 which position the rails substantially parallel to the channel 12 whereby the clamp 18 may be guided forwardly or rearwardly to and from the folding and clamping ~tation 14.

~93 Further, a motor 104 is located adjacent to one of the rail moun-tings 100 for driving the clamp 18 in its movement back and forth along the rai.ls 92, 94. A toothed belt 108 having an upper portion thereof attach~d to the bottom of the clamp base 90, extends around a drive pinion 106 operably connected to the motor 104 to thereby provide the necessary drive connection between the motor 104 and the clamp 18~ The rail mounting 102 is provided with an idler . roller 110 for suppor-ting the belt 108 at the end opposite from the motor 104. Thus, by causing the motox to rotate in a first direction the clamp 18 is drawn toward the folding and clamping station 14, and by operating the motor 104 in a reverse direction, the clamp 18 i~ moved away from the folding and clamping station 14.
The progressive linear clamp 18 further includes a tread carrier 112 which is carried by a carrier bracket 113 attached to a pair of levers 114, 116. The levers 114, 116 are each attached to the clamp base 90 at pivot points 118 : located on a rearward side of the clamp base 90. Thus, the tread carrier 112 is mounted for pivotal movement about the pivot points 118 such that the tread carrier 112 may move toward and away from the table lU in a substantially vertical plane.
The pivokal movement of the arms 114, 116 is controlled by a pair of pancake cylinaers 120, 122 which are supported from the clamp base 90 by means of a pair of cylinder brackets 124, 126. The cylinders 120, 122 are of a double acting type such that they may be actuated to e.ither lift the tread carrier 112 or exert a downward pressure to ~ ~3 .

thereby control the amount of pressure applied by the clamp 18 while clamping the web material.
The tread carrier llZ is formed as a clam ~hell structure of front and rear housing halves 128, 130 which enclose a plurality of pressure roller wheels 132 arranged longitudinally along the interior of the tread carrier 112.
The roller wheels 132 are mounted for rotation within the tread carrier 112 by means of axle bolts 134 extending between the front and rear housing halves 128, 130.
The lower edge of the roller wheels 132 extend slightly beyond the lower edge of the front and rear housing halves 128, 130 ana the endless belt 20 extends along the lower edge of the roller wheels 132 to thereby define a tread for the progressive linear clamp 18. To thi~ end, the roller wheels 132 are preferably formed with a V-groove and the belt 20 is a V-belt whereby alignment between the roller~ 132 and the belt 20 is maintained. In addition, the outer side of the be~t 20 may be provided with outwardly extending transverse ribs or teeth 136 for enbancing the contact and preventing relative movement between the belt 20 and the web material 11.
The location of the upper run of the belt 20 is maintained by means of a pair of idler wheels 138, 140 which maintain the belt 20 in contact with the upper portion of the roller wheels 132 as the belt 20 passes to and from the ends of the tread carrier 112. In addition, the belt 20 is guided over a drive wheel 142 positioned between and above the two idler wheels 138, 140.
The drive wheel 142 is driven by means of a rack and pinion assembly located at the rear side of the clamp ~ ~ t~ tf~ J~

18. The rack and pinion a~sembly includes a rack 144 supported on the rear plate 36 and a pinion gear 146 mounted to the ala~p base 90 by means of a bealring assembly 148 such that the pinion gear 146 is continuously held in contact 5 with the rack 144 to thereby rotate a stub shaft 150 as the progressive linear clamp 18 is moved along the bed 10, The stub shaft 150 is connected to a female spline shaft 152 through a univer~al joint 154. The female spline shaft 152 is in turn connected to a male spline shaft 156 to thereby form a splined slide coupling allow~ng relative longitudinal movement between the two shafts 152 and 156. Finally, the male spline shaft 156 is connected to a drive shaft 158 through a universal joint 160, and the drive shaft 158 is connected to the drive pulley 142 to thereby drive the belt 20.
Thus, the universal joints 154, 160 and sliding coupling formed by the splined shafts 152, 156 allow the drive shaft 158 to b~ moved vertically relative to the stub shaft 150 such that, regardless of the particular vertical position of the tread carrier 112, the rack and pinion assembly will continue to drive the belt 20 around the roller wheels 132.
It should be noted that the relative diameters of the pinion gear 146 and drive pulley 142 are selected ~uch that the linear speed of the belt 20 relative to the lower surface of the tread carrier 112 will be equal to the linear speed of the progre~sive linear clamp 18 relative to the table 10. In thi~ manner, the belt 20 will be driven at a speed such that there will be no relative movement between the table 10 and the portion of the belt 20 passing along the lower side of the roller wheels 132. Thus, as the tread carrier 112 passes over the combined structure of -the folded webbing and netting material, the belt 20 will be laid down on the webbing material 11 to clamp it in place in ~uch a manner that there will be no relative movement between the belt 20 and the webbing material 11 which would cause the relative position between the netting 13 and the webbing 11 to become distorted.
It should also be noted that the idler rollers 138, 140 are mounted to the carrier bracket 113 by means of adjustable bars 162, 164. Each of the bars 162, 164 is provided with an elongated slot 166, 168 engaged by bolts 170 for holding the bars 162, 164 in place. The slots 166, 168 provide means whereby the bars 162. 164 may be adjusted longitudinally of the tread carrier to thereby vary the tension applied by the idler rollers 138, 140 to the belt 20.
Referring to Fig. 5, the feed mechanism 22 is similar to conventional feed mechanisms which are known in the sewing art for conveying material through a sewing machine. The feed mechanism 22 includes an upper carriage 200 and a lower carriage 202 wherein the lower carriage 202 is mounted for vertical movement relative to the upper carriage 200.
The upper carriage 200 includes a plurality of bearings 204 for receivinc~ a plurality of guicle rods 206 which are rigidly mounted to the lower carriage 2U wherehy the movement of the lower carriage 202 relative to the upper carriage 200 is guided. In addikion, the upper carriage 200 is provided with a plurality of double-acting air cylinders 208. The piston portion 209 vf each air cylinder 208 is connected to the lower carriage 202 to thereby effect vertical movement of the lower carriage 202 upon actuation of the air cylinders 208.
The lower carriage 2~2 includes a plurality of spring fin~ers 210 extending rearwardly from a lower portion thereof. The spring fingers 210 include saw tooth edges which are oriented downwardly for engagement with the webbing material 11 within the channel 12 when the lower carriage 202 is moved to a lowermost po~ition. The spring fingers 210 are formed of a resilient material such that they may accommodate slight variations in vertical height which may occur due to variations in th~ thickness of the material to be clamped.
The upper carriaye 200 is supported from the support rail 24 by means of a suspension bracket 212 which is supported from a lowermost portion of the support rail 24. The support rail 24 is of a conventional design and may include a support track Inot shown) and a motor driven belt drive 214 for moving the feed mechani~m 22 linearly along the table 10 and into contact with the material in the folding and clamping station 14.
In a typical operation using the above-described device, a ~trip of webbing material 11 i~ placed within the channel 12 such that it extends up the folding plate 26 and engages in the lip 44, as depicted in Fig. 6. The air cylinders 38 are then actuated to push the folding plate 26 forward over the channel 12 whereby the web material is positioned folded within the channel 12~

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The air cylinder 66 is then actuated to draw the pivot arm 64 rearwardly such tha-t the clamping finger~ 28 are ~imultaneously pivoted or moved forwardly toward the channel 12. Subsequently, the air cylinder~ 70 are ~imultaneou~ly actua-ted to force the tang portion 78 of the clamp fingers 28 downwardly through the slots 46 in the folding plate 26 and into clamping engagement with the webbing material 11 adjacent to the fold line thereof, a~
depicted in FigO 7.
With the webbing material 11 thus clamped in place within the channel 12, the air cylinder 38 is actuated to pull the folding pla-te 26 upwardly out of engagement with the webbing 11 while the clamping fingers 28 remain in position to clamp the folded webbing 11.
The thus folded webbing defines a pair oi free lip portions positioned in facing relationship with each other and extending forwardly of the clamping fingers 28. An operator may then manually insert a length of flexible netting 13 between the lip portion~ starting at the leftmost end of the webbing 11, ~s ~een in Fig. 8.
Referring to Fig, 8, as the netting 13 is inserted within the webbing 11, the operator may actuate a foot pedal (not ~hown) to thereby power the motor 104 to draw the progre~sive linear clamp 18 toward the folding and clamping ~tation 14. In addition, the cylinders 120, 122 will be actuated to force the tread carrier 112 downwardly with a de~ired pressure in preparation for engaging the combined web and netting material. The rate at which the clamp 18 is advanced may be adju~ted to accommodate the rate at which the particular operator is capable of inserting the netting ~.,? ~ ~ f ~ t material 13 between the webbing 11, and in any event the operator controls clamp advancement with the foot pedal.
As noted above, the pinion CJear 146 operate in combination with the rack 144 to cause the belt 20 to advance at the same lineal speed as the tread carrier 112 is advanced such that no relative movement occurs between the webbing material 11 and the belt surface in contact with the webbing material 11. Thus, the operator may cause the progre~sive linear clamp 18 to advance incrementally as additional amount~ of netting is in~erted between the webbing material 11. Further, if the operator should misestimate the amount of netting material 13 to be inserted into the web 11, the motor 104 may be reversed by the foot actuator to thereby rever~e the movement of the clamp 18 and allow a portion of the netting 13 to be removed.
Once the entire length of the netting edge has been in~erted between the lip~ of the webbing and the progressive linear clamp 18 is po~i~ioned over the entire length of the combined structure, the feed mechanism 22 is advancea along the support rail 24 to a position adjacent to the progre~sive linear clamp 18 on the opposite side from the clamp finger~ 28. With the feed mechanism 22 thus po~itioned, the air cylinders 208 may be actuated to force the ~pring fingers 210 into engagement with the outer longitudinal edge of the lip~ of the webbing 11. In the preferred embodiment, the ~errated teeth of the ~pring finger~ 210 are located approximately 1/8 in. away from the edge of the webbing 11, as depicted in Fig. 9.
With the spring fingers 210 engaged on the webbing 11, the cylinders 66, 70 are actuated to move the clamp S

finger~ 28 back to their retracted position and the cylinders 120, 122 a.re actuated to move the tread carrier 112 upwardly out of contact with the combined webhing and netting structure. The motor 104 is then activated to move the progresqive linear clamp 18 back to its ho~e position to the left of the folding and clamping station 14, as viewed in Fig. 1.
Subsequent to the clamping fingers 28 and progressive linear clamp 18 disengaging from the combined webbing and netting structure, the feed mechanism 22 is moved along the support rail 24 in the direction of the qewing ~tation 16. Aq the feed mechanism 22 moves it slides the combined webbing and netting structure longitudinally through the channel 12. A conventional sewing device is provided for sewing the webbing and netting materials together and the belt 214 i~ preferably actuated to convey the material through the sewing station at a rate which is comparable to the operating rate of the sewing device.
After the sewing operation is completed, the combined webbing and netting structure may be conveyed to a conventional material stacking device ~not shown~.
The operation of the present apparatus may be controlled by means of a conventional microprocessor to automatically feed the completed webbing and netting ~tructure through the sewing sta-tion 16 such that, as the feed mechanism 22 is feeding the completed webbing and netting ~tructure through the sewing ~tation 16, the operator may proceed with anothe.r operation of folding and clamping a ~trip of webbiny 11 and combinincJ the webbing with a length of netting 13. Thus, the present apparatus . ?, ~ ?3 provides a combined structure wherein the operator may initiate the formation of an article while the apparatus completes the ~ewing operation on a preceding article.
Consequently, the pre~ent apparatus provides an advantage over the prior art method~ and apparatus for combining webbing with netting material in that prior art methods require that the webbing and netting be sewn together substantially incrementally as the operator proceeds with the step of inserting the netting into the webbing.
In addition, the present invention provides a convenient means for folding the webbing in half and holding it in such a position to allow an operator to use both hands to insert the netting into the webbing. In particular, the progressive linear clamp provides a convenient temporary means for holding the webbing and netting together until the step of combining the two materials is completed.
It should be noted that the progressive linear clamp may find other application~ wh~re a similar need exists for progre sively clamping a material and wherein it 20 i8 neces~ary to allow an operator to have both hand~ free to perform other operations than holding the material.
Further, it should be apparent that the present method and apparatus may be performed upon other materials than the webbing and netting disclosed in the present application. However, the present apparatus i~ particularly ~uited to performing the above-described operations upon material which is relatively flaccid and difficult to handle, While the method and apparatus herein described con~titutes a preferred embodiment of the invention, it is ;3 r~ 5 to be understood that the invention i~ not limited to this precise method and form o~ apparatus, and tha-t changes may be made therein without departin~ from the ~aope of the invention whiah is defined in the app~nded claims.
What is claimed is:

Claims (12)

1. An apparatus for assisting an operator in the process of placing an edge of a first material into a folded over portion of a piece of second material, particularly where one or both of the materials are flexible and extensible and must be properly apportioned along the length of their joint, the apparatus comprising a first clamp which in an open position thereof can receive and fold over a section of the second material along a fold line and hold the section of the second material immobilized with at least one of its edges free for receiving a portion of the first material into the fold, a second clamp mounted for progressive motion spaced from the fold line and along the second material after the edge of the first material is inserted in the section of second material, and a transfer mechanism for taking the combined first and second material from the progressive second clamp and carrying them to a means for attaching the materials together.

2. An apparatus as defined in claim 1, wherein the first material is an extensible piece which must be apportioned in a generally relaxed state in the fold of the second or binding material and wherein the second clamp holds the two materials immobilized and together while maintaining the relaxed state of the extensible piece as the insertion progresses.

3. An apparatus as defined in claims 1 or 2, further including a table supporting said first clamp and extending around said first clamp so as to afford support to the materials being joined in the apparatus, means for supporting and driving said second clamp in a motion along said table over but spaced from said first clamp whereby said first clamp can be released when said second clamp has secured the desired section of the materials to be joined.

4. An apparatus as defined in claims 1, 2 or 3, wherein said transfer mechanism is movable along said table and into position adjacent and parallel to said second clamp so as to accept the joined but unattached materials from the second clamp and to carry the materials together to a joining apparatus.

5. An apparatus as defined in claim 1, wherein said second clamp includes a movable frame having at least a pair of roller wheels carried thereon spaced apart and with their axes generally parallel, a continuous clamping belt passing about said roller wheels and having an upper flight and a lower flight adjacent and parallel the first clamp, and means for driving said belt along its length while in contact with the folded second material whereby the frame progresses along the joined section of materials and progressively engages and holds the joined section while the operation of placing the edge of the first material into the fold of the second material is continued.

6. Apparatus as defined in claim 5, wherein the means for driving the belt includes a further roller wheel having a portion of the upper flight wrapped therearound, and a controlled drive motor connected to rotate said further roller wheel on demand as the materials are engaged along the section to be joined.

7. Apparatus as defined in any of claims 1-6, including a sewing head located along the table and receiving joined sections of the materials from the transfer mechanism so as to stitch the materials together.

8. Apparatus as defined in claims 3 or 4, wherein said first clamp includes one plate having a folding surface flush with said table and a second movable plate which can be pivoted from an open position away from said one plate and a folding position extending over said one plate to fold a length of second material placed on said plates along the fold line.

9. A method of combining a length of first pliable material into a folded length of second pliable material, comprising folding the length of second material along a fold line to bring a face of the second material against: itself, clamping the length of second material along the fold line leaving at least one free edge of the facing material, progressively inserting a length of the first material into the facing folded material to define their combined position, progressively clamping the joined lengths of the materials as the insertion progresses to immobilize the materials once they are placed into their combined position.

10. The method defined in claim 9, including the further step of transferring the joined length of materials into an attaching means for permanently joining them.

11. The method defined in claim 9, including feeding the joined lengths of materials through a sewing head and stitching the materials into a unified piece.

12. The method defined in claim 10, further including removing the joined materials from the progressive clamping step, as a unit and while maintaining their relative positions, and feeding the joined materials into the attaching means.